Method of attaching fins to cylinders



Nov. 12, 1929. J. PURDY 1,735,213

METHOD OF ATTACHING FINS T0 CYLINDERS Filed Jan. 4, 1928 INVENTOR.

ATTORNEYS Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE I JEWIS J. PURDY, OF SYRACUSE, NEW YORK, A SSTGNOB, BY MESNE ASSIGNMENTS, '10

FRANKLIN DEVELOPMENT CORPORATION, OF SYRACUSE, NEW YORK, A CORPORA- TION OF NEW YORK METHOD OF ATTACHING PINS TO CYLINDERS Application med January 4, ms. Serial No. 244,509.

This invention relates to joinin eat radiating fins of a metal having relatlvely high heat conductivity as copper to a metal body having less heat conductivity as a cast iron cylinder, and has for its object a particularly simple and eflicient method for uniting heat radiating fins as copper fins to cast iron cylinders of an internal combustion engine, by which method uniform, good mechanical and heat conducting joints are quickly and economically made. J

The invention consists in the novel steps hereinafter set forth and claimed.

In describing this invention, reference is.

made to the accompanying drawing which is a diagrammatic view illustrating my method of applying fins to cylinders.

- This method comprises generally, arranging the fins which arepreferably of copper with angular base flanges overlying the ished peripheral surface of the cylinder, and burning the flange on the cylinder by melting the flange and underlying portion of the cylinder by applying the heat to the outer side of the flange until the flange is fused and also, the underlying portion of the cylinder melted or softened so that the metal of the flange runs into the molten metal of the cylinder forming an alloy therewith; thus thermal or heat-conducting joint. A

The cylinder casting is firstrough machined and the peripheral surface to w oh the .fins are to be applied finished by grinding. The fins 1 are joined successively, each belng arranged with its base flange 2 overlying the finished peripheral surface 3 of the cylmd'er.

The flanges here shown are also formed 'with angular, flanges 4 at their outer edges so bent as to form a jacket. The heat is applied by passing a carbon electrode 5 of about one-quarter inch in diameter and tapered to a point, along the outer surface of the flange 2. The other electrode 6 of.the electric circuit is connected to the cylinder. The current used is approximatel 40 volts at 100 amperes and the carbon e ectrode is set at A about an angle of 45 with the side surface of the fin. That action of this electrode and the are is a burning in or burning on action rapidly and uniformly conducted from the cylinders than by fins attached to the cylinder.

by casting the cylinder about the margins of the fins on and in the mold with their margins periphery into the cylinder forming mold cavity or by fins welded .to the cylinder by heating the cylinder. The latter method of heating the cylinder has a detrimental annealing effect on the cylinder. I

The fins are applied one by one and in applying the last two or three fins, it is necessary to bend the fins out of their radial paths sufliciently to make room for the electrode 5.

After the welding is completed, these fins so bent are straightened back to their normal position.

I .By this process not only are fins attached with perfect thermal and mechanical joints without detrimentally affecting the iron of the cylinder but also the cylinder can be more economically produced than by the methods heretofore employed.

WhatI claim is:

1. The process of attaching fins to cast iron glinders consisting in heating angular a on the inner edges of the fins and over ying the cylinder Wall from the outer sides of the flanges until the flanges are fused and the underlying or local ortion only of the cylinder wall melted to ess degree and sufiiciently to permit the fused fins to run into the pores of the melted cast iron and form an alloy with the underlyinglocal portion of the cylinder.

2. The process of attaching fins having greater conductivity than cast iron to cast iron cylinders consisting in burning the fins on the cylinders b heatin angular flanges alongthe inner 1 ing the cylinder wall, by heat applied to the outer sidefof the flanges until the flan and. the underlying local portion of $2 ges of t e fins and overcylinder are melted to difierent degrees of softness. 

